Furnace Blower Motor RUN CAP failed....

Thread Starter


Joined Aug 6, 2005
Im wondering if my huge 1/2 horspower electric blower motor for my home furnace/ central air system is failing and caused the capacitor to fail, or whether the caps just fail on their own sometimes. The fan/motor turns freely by hand, and I noticed that the fan was slowly losing power over a number of days. The reason why i know this is that the vents were all sweating (condensing) on the outside the other day when i went down to put roach poison (dirt basement) down there. Anyways, the day the motor actually stopped turning, it seemed to be getting less and less powerful, then finally just stopped. or failed to restart on a cycle, not sure which. Here is the picture of the Cap:

Obviously it is bad, im just hoping to confirm to myself that they *DO* just fail on their own... THANKS IN ADVANCE!!!!

-RS in Birmingham, AL (hoping to get A/C system blowing cold by monday morning!!!)


Joined Apr 20, 2004

Yep, they will do that. Not every one does, though, and the replacement may last forever. Funny how they only go out in really hot weather, anin't it?

That's a standard value and voltage rating, so you should have no trouble getting a replacement.


Joined May 16, 2005
Checking times & dates, you've probably already replaced the cap. If it should happen to fail again in a year or two, then keep the following in mind:

Increased temperature de-rates capacitor working voltages. I don't know if your system is getting hot enough for that to come into play or not. For an extra five bucks or so, you can purchase a 5uf 440volt oval run cap. It will go longer before failing if temperature is an issue.